1. Marienhospital Bruehl, Germany
2. Faculty of Medicine, University of Cologne, Germany
3. Vascular Institute Central Switzerland, Aarau, Switzerland
4. University of Applied Sciences Furtwangen, Villingen-Schwenningen, Germany
5. Faculty of Medicine, University of Lucerne, Switzerland
6. University of Bern, Switzerland
7. Surrey and Sussex Healthcare NHS Trust, East Surrey Hospital, Redhill, UK
8. Department of Clinical and Experimental Medicine, University of Surrey, Guildford, UK